- 5
- Greece
- kostas_dmkp_jdm
The XJ12 version was announced in July 1972, featuring simplified grille treatment, and powered by a 5.3 L V12 engine (coupled to a Borg Warner Model 12).[6] The car as presented at that time was the world's only mass-produced 12-cylinder four-door car, and, with a top speed "around 140 mph" (225 km/h) as the "fastest full four-seater available in the world today". Although it had, from the car's launch, been the manufacturer's intention that the XJ would take the twelve-cylinder engine, its installation was nonetheless a tight fit, and providing adequate cooling had evidently been a challenge for the engineers designing the installation.[7] Bonnet/hood louvres such as those fitted on the recently introduced twelve-cylinder E Type were rejected, but the XJ12 featured a complex "cross-flow" radiator divided into two separated horizontal sections and supported with coolant feeder tanks at each end: the engine fan was geared to rotate at 1¼ times the speed of the engine rpm, subject to a limiter which cut in at a (fan) speed of 1,700 rpm.[7] The fuel system incorporated a relief valve that returned fuel to the tank when pressure in the leads to the carburetters exceeded 1.5 psi to reduce the risk of vapour locks occurring at the engine's high operating temperature, while the car's battery, unusually, benefited from its own thermostatically controlled cooling fan.
